<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }

        .wrapper {
            padding: 0 200px;
            background-color: gray;
            overflow: hidden;
        }

        .box {
            float: left;
            height: 300px;
        }

        .center {
            width: 100%;
            background-color: green;
        }
        
        .left {
            width: 200px;
            background-color: red;
            margin-left: -100%;
            position: relative;
            left:-200px;
        }

        .right {
            width: 200px;
            background-color: blue;
            margin-left: -200px;
            position: relative;
            right: -200px;
        }

    </style>
</head>
<body>
    <div class="wrapper">

        <div class="box center"></div>
        <div class="box left"></div>
        <div class="box right"></div>

    </div>
</body>
</html>